1. Technical Field
The present disclosure relates to an array substrate, a method of manufacturing of the array substrate, and a display device having the array substrate. More particularly, the present disclosure relates to an array substrate capable of enhancing aperture ratio without reducing capacitance, a method of manufacturing the array substrate, and a display device having the array substrate.
2. Discussion of the Related Art
A liquid crystal display (LCD) device displays an image by controlling light transmittance using an electric field.
An LCD device includes an LCD panel having a liquid crystal cells arranged in a matrix, a driving section driving the LCD panel and a backlight assembly providing light with the LCD panel.
The LCD panel includes an array substrate having a plurality of thin film transistor (TFT), a substrate facing the array- substrate and a liquid crystal layer interposed between the array substrate and the substrate.
The LCD panel is provided with pixel electrodes and a common electrode to apply an electric field to each liquid crystal cell. Pixel electrodes are formed on the array substrate, whereas the common electrode is formed on the substrate. Each of pixel electrodes is connected to a drain electrode of the TFT. The pixel electrode along with the common electrode drives the liquid crystal cell to apply an electric filed in response to a data signal applied via the TFT.
Hereinafter, a conventional LCD device will be explained referring to FIG. 1
FIG. 1 is a cross-sectional view illustrating a conventional LCD panel.
Referring to FIG. 1, an array substrate includes a switching device 101, a storage capacitor 102 and a pixel electrode 103.
The switching device 101 includes a gate electrode 104 that is electrically connected to one of the gate lines, a gate insulation layer 105, a source electrode that is electrically connected to one of the data lines, and a drain electrode that is electrically connected to the pixel electrode 103.
When a control signal is applied to the gate electrode 104, a pixel voltage is applied to the pixel electrode 103. An electric field is generated between the pixel electrode 103 of the array substrate and the common electrode of the substrate facing the array substrate.
In response to changes in the electric field that is applied to the liquid crystal layer interposed between the pixel electrode 103 and the common electrode, an arrangement of liquid crystal molecules of the liquid crystal layer is changed to alter optical transmittance, thereby an image is displayed.
The storage capacitor 102 can function as an auxiliary capacitor to maintain the capacitance of the liquid crystal layer for one frame.
When the capacitance of the liquid crystal layer is influenced by the peripheral voltage after receiving the data voltage, the storage capacitor 102 prevents the capacitance of the liquid crystal layer from varying and supplements the auxiliary capacitance to maintain the data voltage for one frame. Therefore, when the capacitance of the storage capacitor 102 increases, a display quality of the LCD panel is enhanced.
The capacitance of the storage capacitor 102 is linearly proportional to the area of the storage capacitor and inversely proportional to the thickness of the dielectric layer of the storage capacitor. In other words, when a thickness of the gate insulation layer 105 decreases and an overlapping area between the two electrodes defining the storage capacitor 102 increases, the capacitance of the storage capacitor 102 increases.
However, when the overlapping area between two electrodes of the storage capacitor 102 increases, an aperture ratio of the LCD panel decreases.